This invention relates to a floppy disk drive control apparatus for controlling a floppy disk drive and, more specifically, a stepping motor control circuit for controlling a stepping motor to cause magnetic heads of the floppy disk drive perform a seek operation.
In the manner known in the art, a floppy disk drive (which may be abbreviated to xe2x80x9cFDDxe2x80x9d) is a device for carrying out data recording and reproducing operations to and from a magnetic recording medium of a floppy disk (which may be abbreviated to xe2x80x9cFDxe2x80x9d) loaded therein. Such a floppy disk drive is typically loaded in portable electronic equipment such as a laptop personal computer, a notebook-size personal computer, a notebook-size word processor, or the like.
The floppy disk drive of the type comprises magnetic heads for reading/writing data from/to the magnetic recording medium of the floppy disk, a carriage assembly for supporting the magnetic heads at a tip thereof with the magnetic head movably along a predetermined radial direction to the floppy disk, a stepping motor for moving the carriage assembly along the predetermined radial direction, and a spindle motor for rotatably driving the magnetic recording medium with the floppy disk held. An operation to move the magnetic heads to a target track is called a xe2x80x9cseekxe2x80x9d operation in the art. This seek operation is carried out by rotating the stepping motor.
An FDD control apparatus is an apparatus for controlling the floppy disk drive. A conventional FDD control apparatus seeks the magnetic heads in a direction (for example, an inner periphery or an outer periphery) designated by an external seek direction signal when a drive select signal is put into an active state of a logic low level and when an external step signal is inputted whether or not a floppy disk is inserted in the floppy disk drive. At any rate, the conventional FDD control apparatus can carry out the seek operation in spite of insertion/noninsertion of the floppy disk.
However, in a case where the floppy disk is not inserted in the floppy disk drive, the conventional FDD control apparatus is disadvantageous in that a seek error occurs and seek noises are raised in the manner which will later be described in conjunction with FIGS. 2A and 2B.
It is therefore an object of the present invention to provide a floppy disk drive control apparatus which is capable of preventing occurrence of a seek error.
It is another object of the present invention to provide a floppy disk drive control apparatus of the type described, which is capable of suppressing seek noises on absence of a medium.
Other objects of this invention will become clear as the description proceeds.
On describing the gist of this invention, it is possible to be understood that a floppy disk drive control apparatus controls a floppy disk drive for driving a floppy disk loaded in the floppy disk drive.
According to an aspect of this invention, the above-understood floppy disk drive control apparatus comprises an arrangement for inhibiting a seek operation when the floppy disk is not loaded in the floppy disk drive.
According to another aspect of this invention, the above-understood floppy disk drive control apparatus comprises a determining arrangement for determining whether or not the floppy disk is loaded in the floppy disk drive. When the determining means determines that the floppy disk is not loaded in the floppy disk drive, an inhibiting arrangement inhibits a seek operation.
On describing the gist of this invention, it is possible to be understood that a stepping motor control circuit controls, in response to an external seek direction signal and an external step signal which are supplied from the outside, a stepping motor to make magnetic heads of a floppy disk drive a seek operation.
According to an aspect of this invention, the above-understood stepping motor control circuit comprises a head target position track counter for producing, in response to the external seek direction signal and the external step signal, a target track position signal indicative of a target track position for the magnetic heads regardless of whether a floppy disk is loaded in the floppy disk drive or not. When the floppy disk is loaded in the floppy disk drive, an arrangement automatically seeks the magnetic heads up to the target track position indicated by the target track position signal by driving the stepping motor.
According to another aspect of this invention, the above-understood stepping motor control circuit comprises a head target position track counter for producing, in response to the external seek direction signal and the external step signal, a target track position signal indicative of a target track position for the magnetic heads regardless of whether a floppy disk is loaded in the floppy disk drive or not. When the floppy disk is loaded in the floppy disk drive, an internal step signal producing arrangement is activated to produce an internal step signal. When the floppy disk is not loaded in the floppy disk drive, a head current position track counter is inactivated. When the floppy disk is loaded in the floppy disk drive, the head current position track counter is put into an active state to produce, in response to a selected seek direction signal and a selected step signal, a current track position signal indicative of an actual current track position for the magnetic heads. When the floppy disk is loaded in the floppy disk drive, a comparing circuit compares the target track position signal with the current track position signal to produces an internal seek direction signal and a coincidence signal indicative of coincidence/noncoincidence between the target track position and the current track position. When the coincidence signal indicates the noncoincidence, a seek direction selecting arrangement selects the internal seek direction signal as the selected seek direction signal. When the coincidence signal indicates the coincidence, the seek direction selecting arrangement selects the external seek direction signal as the selected seek direction signal. The seek direction selecting arrangement supplies the selected seek direction signal to the head current position track counter. When the floppy disk is loaded in the floppy disk drive, a step signal selecting arrangement is activated. The step signal selecting arrangement selects the internal step signal as the selected step signal when the coincidence signal indicates the noncoincicence. The step signal selecting arrangement selects the external step signal as the selected step signal when the coincidence signal indicates the coincidence. The step signal selecting arrangement supplies the selected step signal to the head current position track counter. A driving arrangement drives the stepping motor on the basis of the selected seek direction signal and the elected step signal.